Bankers in Europe face a cap on bonuses as early as next year, following agreement in Brussels on Thursday to introduce what would be the world's strictest pay curbs, in a move politicians hope will address public anger at financial-sector greed.
The provisional agreement, announced by diplomats and officials after late-night talks between EU country representatives and the bloc's parliament, means bankers face an automatic cap on bonus payouts at the level of their salaries.
If a majority of a bank's shareholders vote in favour, that ceiling can be raised to two-times pay.
"For the first time in the history of EU financial market regulation, we will cap bankers' bonuses," said Othmar Karas, the Austrian lawmaker who helped negotiate the deal.
Such limits to bankers' pay, which is set to enter EU law as part of a wider overhaul of capital rules to make banks safer, will be popular on a continent struggling to emerge from the ruins of a 2008 financial crisis.
But it represents a setback for the British government, which had long argued against such absolute limits. The City of London, the region's financial capital with 144,000 banking staff and many more in related jobs, will be hit hardest.
As it stands in draft legislation, the cap would also apply to bankers employed by an EU institution but based elsewhere globally, in a centre such as New York, according to one official.
There are also provisions for adjusting the value of long-term non-cash payments, so that more bonus can be paid in that way without breaking through the new ceiling.
Ireland, which holds the rotating EU presidency and negotiated what it called a "breakthrough," will now present the agreement to EU countries.
The backing of a majority of EU states is needed for the deal to be finalised. One member of the European parliament privately signalled that the deal could yet change, pointing to the "reservations" of some EU countries.
Irish Finance Minister Michael Noonan said he would ask his peers to back it at an EU ministers' meeting on March 5 in Brussels.
The change in the law is set to be introduced as part of a wider body of legislation demanding banks set aside roughly three times more capital and build up cash buffers to cover the risk of unpaid loans, for example.
Some experts have criticised the EU, however, for failing to keep to all of the so-called Basel III code of capital standards drawn up by international regulators to reform banking after the financial crash.
The agreement on Thursday will also require banks to outline profits and other details of operations on a country-by-country basis.
A ceiling on bonuses, the only one of its kind globally, is perhaps the most radical aspect of the new rules.
Many in banking argue, however, that such reform will do little to lower pay in finance, where head-hunters say some annual packages in London approach 5 million pounds ($US7.6 million).
"If the cap is implemented, it could result in significantly more complex pay structures within banks as they try to fall outside the restrictions to remain competitive globally," said Alex Beidas, a pay specialist with the law firm Linklaters.
An earlier attempt to limit bankers' pay with an EU law forcing financiers to defer bonus payments over up to five years merely prompted lenders to increase base salaries.
But it would be harder for banks to raise base pay this time around. The bonus rules will come as part of wider legislation setting higher capital standards for banks, increasing their costs and curbing freedom to hike salaries.
Hedge funds and private equity firms will be excluded from such curbs, although they face restrictions on pay later this year under another EU law.
Nonetheless, the curbs on bankers could have a spillover effect on the nearly 700,000 people who work in financial and professional services in London.
About 27 billion pounds ($US41 billion) of bonuses have been spent over the past decade on real estate in the British capital, according to data compiled for Reuters by property firm Savills.
"This could push British political opinion and opinion in the City of London several notches more hostile to the EU than it is already," said Charles Grant of the Centre for European Reform, a think tank.
The restrictions planned by Brussels may be overtaken by events in an industry where slack activity has already driven down most bonuses to twice salary or lower.
Having peaked in 2008 at 11.5 billion pounds ($US17.4 billion), the bonus pool in London fell to 4.4 billion pounds last year, according to research by the Centre for Economics and Business Research. It predicts that pool will be just 1.5 billion pounds this year and fall further in the future.
On Wall Street, by contrast, the securities industry's bonus pool was expected to total $US20 billion last year, with the average cash bonus rising an estimated 9 per cent to almost $US121,900, New York state's comptroller said this week.
"There are some in the US who will think it's a good idea to do the same," said Nicolas Veron, the Peterson Institute for International Economics think tank in Washington.
"But the mainstream here would say that regulating pay is going to be circumvented by the banks and will ultimately hurt the economy."